rrweb + cypress

hooks.js

const sessionId = Cypress.env('sessionId');
const appFrame = window.parent.document.querySelectorAll('iframe')[0];

Cypress.on('window:load', () => {
  appFrame.contentWindow.eval(`
    const request = new XMLHttpRequest();
    request.open('GET', 'https://cdn.jsdelivr.net/npm/rrweb@0.7.4/dist/rrweb.min.js', false);
    request.send('');
    const script = document.createElement('script');
    script.type = 'text/javascript';
    script.text = request.responseText;
    document.head.appendChild(script);
    if (!window.__events__) {
      window.__events__ = [];
    }
    rrweb.record({
      emit(e) {
        e.sessionId = '${sessionId}'
        window.__events__.push(e)
      }
    })
  `)
})

Cypress.on('fail', (error) => {
  appFrame.contentWindow.eval(`
    if (window.__events__) {
      const body = JSON.stringify({ events: window.__events__ })
      window.__events__ = []
      const request = new XMLHttpRequest();
      request.open('POST', YOUR_BACKEND_API, false);
      request.setRequestHeader('content-type', 'application/json');
      request.send(body);
    }
  `)
  throw error
})